Kris Boyd, before Rangers travelled to the home of arch rivals Celtic on Sunday, expressed his concerns that Philippe Clement was presiding over a weaker squad of players now than he had been at the end of May. Boyd’s point, it’s fair to say, was only exacerbated by one of the club’s most limp, lifeless Old Firm derby displays in some time. Is Vaclav Cerny, who struggled so dramatically against Celtic, the answer to Rangers’ long-running right-wing issues? Can Conor Barron stamp his authority on in the most high pressure of situations as Ryan Jack once did? Are Jefte and Robin Propper upgrades…